The Federal Communications Commission (FCC) has allocated spectrum in the 60 GHz band for commercial wireless applications. The Wireless Gigabit Alliance (WiGig) was developed to promote the IEEE 802.11ad protocol, which operates in this frequency band and is expected to deliver data transfer rates up to 7 Gbps.
Integrated circuits formed in semiconductor dies offer high-frequency operation in millimeter-wave bands. Some of these integrated circuits utilize Complementary Metal Oxide Semiconductor (CMOS), Silicon-Germanium (SiGe), or GaAs (Gallium Arsenide) technology to form the dies.
In millimeter-wave systems, the transmit paths of signals transmitted in the wireless channel need to be compensated for various mismatch conditions occurring in the up-convertor circuit. Some of these conditions manifest as local oscillator (LO) leakage and signal image in the transmitted RF spectrum.
CMOS is the primary technology used to construct integrated circuits. N-channel transistors and P-channel transistors (MOS transistor) use fine-line technology to consistently reduce the channel length of the MOS transistors. Current channel lengths are 40 nm, the power supply of VDD is 1.2V, and the number of layers of metal levels can be 8 or more.
CMOS offers the computing power to perform many of the required compensation techniques to overcome the adverse conditions in the transceiver. Yet, the computing power must be used in a power-efficient manner to ensure that dissipated power is low enough to allow these important transceiver building blocks fabricated in CMOS to be used in mobile applications. This helps conserve the transceiver's battery power while achieving the optimum performance.